1. Field of the Invention
This invention relates to an apparatus with an additionally installable equipment.
2. Description of Related Art
With an image forming apparatus such as, e.g., a printer, a photocopier, a facsimile machine, or the like, for example, with a printer, an additionally installable tray serving as an additionally installable equipment conventionally can be installed in a detachably attachable manner to a printer housing serving as an apparatus housing, and in a case of the printer, the additionally installable tray is disposed to a lower side of the printer housing (see, e.g., Japanese Patent Application Publication Nos. H6-115,725 and H8-157,082).
FIG. 2 is a perspective view showing a conventional printer.
In FIG. 2, numeral 11 is a printer housing while numeral 13 is an additionally installable tray, in which plural positioning holes 12 serving as inserted portions for positioning are formed to extend upward as opening on a bottom surface of the printer housing, while plural positioning pins 14 serving as inserting portions for positioning are formed as projecting upward to parts on an upper surface of the additionally installable tray 13 at positions corresponding to the positioning holes 12.
The printer housing 11 is therefore positioned with respect to the additionally installable tray 13 upon inserting respectively the positioning pins 14 into the positioning holes 12.
With the conventional printer, however, when the additionally installable tray 13 is detached from the printer housing 11, the positioning pins 14 respectively need to be pulled out of the positioning holes 12, thereby rendering this operation troublesome while occasionally causing damages on fitting portions between the positioning hole 12 and the positioning pin 14.
FIG. 3 is a view showing the operation for detaching the additionally installable tray from the printer housing of the conventional printer, and FIG. 4 is a view showing a state of the fitting portion at a time that the additionally installable tray is detached from the printer housing of the conventional printer.
As shown in drawings, when detaching the additionally installable tray 13 from the printer housing 11, an operator needs to pull respectively the positioning pins 14 out of the positioning holes 12 upon lifting up the printer housing 11 as keeping the housing horizontally as possible with putting his fingers into handles 16 formed to an upper end of each side wall of the printer housing 11.
However, when the operator cannot lift up the printer housing 11 with enough force to tilt the printer housing 11 at a tilt angle γ with respect to the additionally installable tray 13 as shown in FIG. 4, the positioning pin 14 undesirably gets caught in the positioning hole 12 at the fitting portion between the positioning hole 12 and the positioning pin 14.
That is, where a vertex side of the tilt angle γ is set as a non-moving-up side while a side separating from the vertex is set as a moving-up side, when the printer housing 11 is tilted, the positioning hole 12 is tilted with respect to the positioning pin 14, so that a ridgeline of the most moving-up side on an inner circumferential surface of the positioning hole 12 and an upper end of a ridgeline of the most moving-up side on an outer circumferential surface of the positioning pin 14 come in contact with each other at point pa on an upper end of the positioning pin 14 while a lower end of a ridgeline of the most non-moving-up side on the inner circumferential surface of the positioning hole 12 and a ridgeline of the most non-moving-up side on the outer circumferential surface of the positioning pin 14 come in contact with each other at point pb on a lower end of the positioning hole 12. Thus, the point pa functions as a point of application of force while the point pb functions as a fulcrum, and as the result, a base of the positioning pin 14 bends with point pc on a lower end of the ridgeline of the most non-moving-up side on the outer circumferential surface of the positioning pin 14 as an application point, thereby resulting in occurrence of a phenomenon such that the positioning pin 14 is deformed by bending, i.e., a pin bending phenomenon.
Furthermore, since the positioning pin 14 is trapped in the positioning hole 12, the additionally installable tray 13 may be lifted up in accordance with lifting motion of the printer housing 11 to suddenly fall down in the middle, thereby occasionally receiving damages.
This invention is to solve the above problems and to provide an apparatus with an additionally installable equipment, in which when the additionally installable equipment is detached from the apparatus housing, the inserting portion for setting a position does not get deformed while the additionally installable equipment does not get damaged due to falling down.